METHOD FOR MAKING POSITIVE LITHOGRAPHIC PRINTING PLATE

摘要

PROBLEM TO BE SOLVED: To provide a method for making a positive lithographic printing plate by which a lithographic printing plate can be made under a wide range of developing conditions when a photosensitive layer is formed by applying and drying a coating solution of a positive photosensitive composition on the surface of a support freely attachably and detachably fixed on the peripheral face of a drum and then the photosensitive layer is subjected to scanning exposure with a laser light source and developed to allow a positive image to appear. SOLUTION: In the method for making a positive lithographic printing plate, a positive photosensitive composition used comprises (A) a photothermal conversion material which absorbs light of a light source for imagewise exposure and converts the light to heat, (B) an alkali-soluble resin and (C-1) an organic acid or its anhydride or (C-2) a nonionic surfactant. COPYRIGHT: (C)2004,JPO